Axonal ephrin-As and odorant receptors: coordinate determination of the olfactory sensory map

Cell. 2003 Aug 8;114(3):311-22. doi: 10.1016/s0092-8674(03)00568-3.


Olfactory sensory neurons expressing a given odorant receptor (OR) project with precision to specific glomeruli in the olfactory bulb, generating a topographic map. In this study, we demonstrate that neurons expressing different ORs express different levels of ephrin-A protein on their axons. Moreover, alterations in the level of ephrin-A alter the glomerular map. Deletion of the ephrin-A5 and ephrin-A3 genes posteriorizes the glomerular locations for neurons expressing either the P2 or SR1 receptor, whereas overexpression of ephrin-A5 in P2 neurons results in an anterior shift in their glomeruli. Thus the ephrin-As are differentially expressed in distinct subpopulations of neurons and are likely to participate, along with the ORs, as one of a complement of guidance receptors governing the targeting of like axons to precise locations in the olfactory bulb.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Axons / metabolism*
  • Ephrin-A3 / genetics
  • Ephrin-A3 / metabolism*
  • Ephrin-A5 / genetics
  • Ephrin-A5 / metabolism*
  • In Situ Hybridization
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Neurons, Afferent / cytology
  • Neurons, Afferent / metabolism
  • Olfactory Bulb / anatomy & histology
  • Olfactory Bulb / physiology*
  • Olfactory Marker Protein
  • Receptors, Odorant / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Sensation / physiology*


  • Ephrin-A3
  • Ephrin-A5
  • Nerve Tissue Proteins
  • Olfactory Marker Protein
  • Omp protein, mouse
  • Receptors, Odorant
  • Recombinant Fusion Proteins